Kirby 64: The Crystal Shards was the first and only Nintendo 64 entry in HAL Laboratory's long-running Kirby series. The game is a 2.5D platformer, where the action unfolds as if it was side-scrolling but with 3D graphics and variable camera angles that automatically change to reflect the player's position and progress throughout levels.

The core gameplay is faithful to the Game Boy and SNES Kirby titles; players can run, jump, and fly, as well as devour enemies and "copy" their powers for their own use as special abilities. Kirby 64 is the only title in the series that features the ability for players to combine two Copy Abilities to create either upgraded or entirely new ones, though Kirby Squeak Squad has a few (limited) combinations.

Levels are spread across six different planets ruled by bosses, which Kirby must defeat in order to retrieve the titular Crystal Shards needed to defeat the evil Dark Matter. The game also features three minigames which up to four players can compete in multiplayer.